2023 Commercial Electrical Inspector – Practice Exam

1. Where mating dissimilar metals at battery terminations, what must be used if recommended by the battery manufacturer’s installation and instruction manual?

2. What must be done to all cut ends of LFNC?

3. For tank storage installations inside buildings, what classification applies to all equipment located below grade level?

4. Interconnection between a surge arrester protecting a transformer and the secondary grounded circuit conductor or grounding electrode conductor requires a metal interconnection if what additional grounding connection exists?

5. If an energy management system (EMS) is used to limit the current to a feeder or service, the single value used in load calculations shall be equal to what setting of the EMS?

6. A listed appliance distinctly marked as protected by a system of double insulation is not required to be terminated with a grounding-type attachment plug when connecting which appliance?

7. What is the minimum rating (hp or watts) for kitchen equipment that is fastened in place (other than cooking, heating, cooling) and is included in the calculations of 220.56?

8. Locations where metal combustible fibers/flyings are present shall be classified as what type of hazardous location?

9. Surge arresters shall be made inaccessible to unqualified persons unless they are what?

10. Where single conductor cables of an AC circuit are connected in parallel, how must the conductors be installed in metal wireways?

11. On 3-phase, 3-wire circuits, an overcurrent relay element in the residual circuit of the current transformers shall be permitted to replace which component?

12. In damp or wet locations, enclosures installed in wet locations must be what?

13. For track lighting in commercial occupancies, what is the additional load that must be included for every 600 mm (2 ft) of lighting track or fraction thereof?

14. Where two or more motors have the same highest rated-load current, how many of them are considered the highest rated (largest) motor?

15. Where must splices and taps be made within the ENT system?

16. Where equipment grounding is required in an ENT system, what must be installed?

17. Storage battery charging equipment in Class III locations must be located in separate rooms constructed to prevent the entrance of ignitible amounts of flyings or lint and must also be what?

18. Where an on-site standby generator is used to supply a fire pump, is an additional disconnecting means permitted between the generator and the controller?

19. For impedance or ungrounded systems over 1000 volts, what is considered the maximum continuous operating voltage for surge arrester rating selection?

20. The cell line working zone is not required to extend through or beyond which of the following structural components?

21. If removing a grounding connection in normal power source equipment interrupts the connection to the alternate source(s) grounded conductor, what specific hazard must the warning sign indicate for the Emergency System?

22. What is the minimum required size for SPD line conductors made of aluminum?

23. Circuit breakers or switches located in power outlets complying with 626.31(B) shall be permitted as what?

24. Conductors entering or leaving wet or corrosive locations shall have what formed on them?

25. What is the maximum vertical spacing interval for supporting 350 kcmil aluminum or copper-clad aluminum conductors in a vertical raceway?

26. Direct burial cables are permitted to be spliced or tapped without the use of splice boxes if the taps and splices are watertight and protected from what?

27. An industrial control panel shall not be installed where the available fault current exceeds what marked rating?

28. Overload protection for each ungrounded service conductor shall be provided by an overcurrent device that has a rating or setting not higher than what value?

29. The repair of hard-service cord and junior hard-service cord is permitted if the conductor size is what AWG or larger?

30. A low-voltage lighting system may be assembled from listed parts provided the secondary circuit utilizes which of the following?

31. What is the minimum ampere rating required for the disconnecting means when loads are variable?

32. What specific marking is required on nonmetallic boxes used with metal raceways if they rely on integral bonding means?

33. The authority having jurisdiction (AHJ) may grant exception for the installation of conductors and equipment used to connect the electric utility supply system to the service conductors, provided such installations are located where?

34. If ungrounded service-entrance conductors are paralleled in two or more raceways or cables, the grounded conductors must also be installed in parallel and the size of each grounded conductor shall not be smaller than what minimum size?

35. Where oil switches or air, oil, vacuum, or sulfur hexafluoride circuit breakers constitute the service disconnecting means, an isolating switch is required to be installed where?

36. Enclosures for overcurrent devices shall generally be mounted in a vertical position, but listed busway plug-in units are permitted to be mounted in which orientation?

37. Where flammable gases or vapors are released within a cannabis oil booth, how is the space within 3 ft. of any opening classified?

38. Electrical equipment with a metal enclosure is permitted to be installed in other spaces used for environmental air (plenums), provided what condition is met regarding associated wiring material?

39. Which type of backfed circuit breaker is permitted to omit the additional fastener normally required by 408.36(D)?

40. Where bus enclosures terminate at machines cooled by flammable gas, what must be provided to prevent accumulation of flammable gas in the enclosures?

41. Which type of metal-covered multiconductor cable is specifically exempted from the requirement to use a marker tape located within the cable?

42. If a conductor with white insulation is reidentified to serve as an ungrounded conductor in a 240-volt circuit, the reidentification tape must encircle the insulation and must be applied where?

43. Ungrounded conductors tapped from a grounded system must be controlled by switching devices that manually switch all poles together if the device serves as a disconnecting means for which appliance?

44. What is the maximum size (metric designator) permitted for EMT?

45. A field-wiring compartment for service or feeder connections must be located so that the connections may be readily inspected after the MDC is installed, and must permit the connection to be introduced and what else?

46. Under what condition is LFMC permitted to be unsecured and unsupported?

47. Which wiring method is permitted to be installed in exposed or concealed locations under metal-corrugated sheet roof decking without maintaining the 38 mm (1 1/2 in.) spacing requirement?

48. In a 3-phase, 4-wire, delta-connected system used in an industrial control panel, which phase must be the phase having the higher voltage to ground?

49. Which system is permitted to be supplied by an additional feeder or branch circuit to a building or structure?

50. If a fuse is used to protect a feeder or branch circuit, how many fuses must be connected in series with each ungrounded conductor?

51. A single installation of surge arresters is permitted to protect a number of interconnected circuits if no circuit is exposed to surges while disconnected from what device?

52. For a circuit operating at 50 kV to ground, what is the minimum clear distance required between a fence enclosure and exposed live parts?

53. What specific marking is required on the disconnecting means for all Energy Storage Systems (ESS)?

54. Outlets for heavy-duty lampholders shall be calculated at a minimum of how many volt-amperes?

55. Overload protection for motor-compressors and equipment used on 15text{-} or 20(ampere), 120 volt , or 15(ampere), 208text{-} or 240 volt , single-phase branch circuits that are not cord- and attachment-plug-connected is permitted in accordance with 440.54. What must the short-circuit and ground-fault protective device protecting the branch circuit have?

56. What is the maximum duration that temporary feeder conductors used to connect a generator for repair or emergencies are permitted to operate without ground-fault protection of equipment?

57. A cable, raceway, or box installed under metal-corrugated sheet roof decking must be supported so there is not less than what minimum clearance measured from the lowest surface of the roof decking to the top of the installation?

58. For the purposes of GFCI protection requirements, how shall the distance from a receptacle be measured?

59. When may an Emergency System feeder supply both emergency and nonemergency loads from the same common bus using overcurrent protection?

60. Except for multiwire circuits tapped at the load end, all conductors of a multiwire branch circuit shall originate from which location?

61. Under what specific conditions is the temporary connection of a portable generator permitted without transfer equipment for an Optional Standby System?

62. Installations of railways used exclusively for signaling and communications purposes are covered by this Code. True or False?

63. What is the maximum distance RMC shall be securely fastened from each outlet box, junction box, cabinet, or other conduit termination?

64. How shall the terminal intended for connection to the grounded conductor in polarized receptacles be identified?

65. The required surge-protective device (SPD) must be an integral part of the service equipment or located where?

66. Refrigerant machinery rooms using ammonia may be classified as “unclassified” if equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding what ppm?

67. What condition requires flexibility for LFNC use?

68. Cartridge fuses and fuseholders of the 300-volt type shall be permitted to be used in single-phase line-to-neutral circuits supplied from a 3-phase, 4-wire, solidly grounded neutral source where the line-to-neutral voltage does not exceed what voltage?

69. In addition to lamp wattage and manufacturer identification, what marking is required on a luminaire that requires supply wire rated higher than 60 (C) / 140 (F)?

70. Type 3 SPDs are permitted to be installed on the load side of branch-circuit overcurrent protection up to the equipment served. If specified in manufacturer’s instructions, what is the minimum conductor distance required from the service or separately derived system disconnect?

71. Approved means shall be provided for maintaining continuity of the equipment grounding conductor between the fixed wiring system and the non–current-carrying metal portions of which three equipment types?

72. For a large-scale PV electric supply station, where must the fence grounding requirements and details be included?

73. When calculating the floor area for a dwelling unit, which area must NOT be included?

74. General-use snap switches used with open wiring on insulators must be mounted on insulating material that separates the conductors at least what distance from the surface wired over?

75. For indoor electrical equipment, which enclosure type provides protection against falling dirt, falling liquids, and settling airborne dust but NOT against circulating dust or hosedown?

76. A Class II, Division 1 location is defined as a location where combustible dust is in the air under normal operating conditions in quantities sufficient to produce what?

77. How deep must a metal underground water pipe be in direct contact with the earth to be considered a grounding electrode?

78. Where an interconnection is made through a spark gap for an ungrounded or unigrounded primary system, there must be at least one other ground on the grounded conductor of the secondary that is not less than what distance from the surge-arrester grounding electrode?

79. When an electrical installation is modified affecting the available fault current at the service, what action is required regarding the existing field marking?

80. Transformers must individually comply with the requirements of this article unless specific provisions allow for interconnection and operation as what?